They either heard something or smelled something odd. I like to hunt them when it's windy because I can get real close. They see about as well as we do, but they're usually focused on the ground and finding food, so they seem to rely on scent and hearing to alert them to danger. Any little noise or smell and they'll casually move on. They usually don't spook too much until they identify what's coming. Good luck, it sounds like fun. Make sure you post pics if you get one.
